The abdominal wall in humans is made up of fat and muscles joined together by aponeuroses. Sometimes a hiatus occurs at the aponeuroses that allows part of the peritoneum to protrude which then constitutes a sac, or else a hernia, containing either fat or part of the intestines. Hernias or eventrations (hernia occurring over a surgical parietal scar) appear as an excrescence at the surface of the skin and are qualified as hernias or eventrations, for example umbilical or inguinal depending on their locations.
The most conventional method for repairing a hernial defect involves attaching suture threads under tension. However, this type of repair is a source of pain for the patient and, due to the high tensions, have a not insignificant risk of tearing muscles and aponeuroses via the sutures and/or of recurrence of the hernia.
In order to minimize the risks of recurrence, surgeons frequently insert a prosthesis made of a synthetic mesh which replaces or reinforces the weakened anatomical tissues without requiring the edges of the damaged tissues to be brought together. However, such a prosthesis is subjected to an abdominal pressure which tends to expel it outwards. Hence the effectiveness of the prosthesis, and therefore the minimization of the risks of relapse, depend in large part on the attachment of this prosthesis. Firstly, the spreading-out of the prostheses, which are often flexible, proves difficult so that they have a tendency to form folds over the abdominal wall. The lack of perfect spreading-out leads to a risk of herniation of the peritoneal sac and increases the possibilities of recurrence. The surgeon therefore tries to ensure that no part of the prosthesis is folded over and that no viscera or no part of the intestines is interposed between the prosthesis and the abdominal wall. Then, poor positioning of the sutures or poor attachment of the prosthesis risks twisting this prosthesis and creating tensions.
In order to attempt to overcome these drawbacks, various types of prosthesis have been proposed.
Published patent application US 2005/0159777 discloses a device intended to facilitate the spreading-out of the prosthesis in the peritoneal space using an inflatable balloon. However, the correct positioning of the prosthesis is difficult to maintain between the removal of the balloon and the introduction of the stapling device. Furthermore, the use of this device requires a prior incision in the peritoneal sac at the risk of tearing it. Finally, the positioning of the staples is carried out without direct visual control, by means of a complex stapler, which does not make it possible to ensure that no small intestine loop or that no fat fold is interposed between the prosthesis and the posterior face of the abdomen.
Published international patent application WO-A-00/07520 discloses a flexible mesh prosthesis that is kept taut by a ring having a flexibility, which enables it to be deformed then to resume its initial shape. However, it is observed that the introduction of this type of prosthesis is made difficult due to the presence of the ring. Furthermore, these flat and rigid prostheses do not always fit correctly to the convexity of the peritoneal sac and viscera. Moreover, this type of prosthesis does not make it possible to ensure correct attachment and centring.
One variant disclosed in published patent application US 2006/0282105 consists of a prosthesis containing a resilient rod capable of keeping the prosthesis in the deployed position. The attachment of the prosthesis is obtained by a resorbable tether passed through the abdominal wall. Keeping the prosthesis in position is then only ensured by the abdominal pressure and a risk of herniation of the peritoneal sac is therefore not ruled out.